On Fri, Sep 04, 2020 at 02:46:53PM +0530, Ritesh Harjani wrote:
> After moving ext4's bmap to iomap interface, swapon functionality
> on files created using fallocate (which creates unwritten extents) are
> failing. This is since iomap_bmap interface returns 0 for unwritten
> extents and thus generic_swapfile_activate considers this as holes
> and hence bail out with below kernel msg :-
>
> [340.915835] swapon: swapfile has holes
>
> To fix this we need to implement ->swap_activate aops in ext4
> which will use ext4_iomap_report_ops. Since we only need to return
> the list of extents so ext4_iomap_report_ops should be enough.
>
> Reported-by: Yuxuan Shui <yshuiv7@xxxxxxxxx>
> Fixes: ac58e4fb03f ("ext4: move ext4 bmap to use iomap infrastructure")
> Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>
> ---
> [Tested xfstests with -g swap; Tested stress-ng with --thrash option]
Seems reasonable to me (at least from the iomap and "did you run QA?"
end...)
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
>
> fs/ext4/inode.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 1556cabd3a7d..9ac0f83e6fbe 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -3605,6 +3605,13 @@ static int ext4_set_page_dirty(struct page *page)
> return __set_page_dirty_buffers(page);
> }
>
> +static int ext4_iomap_swap_activate(struct swap_info_struct *sis,
> + struct file *file, sector_t *span)
> +{
> + return iomap_swapfile_activate(sis, file, span,
> + &ext4_iomap_report_ops);
> +}
> +
> static const struct address_space_operations ext4_aops = {
> .readpage = ext4_readpage,
> .readpages = ext4_readpages,
> @@ -3620,6 +3627,7 @@ static const struct address_space_operations ext4_aops = {
> .migratepage = buffer_migrate_page,
> .is_partially_uptodate = block_is_partially_uptodate,
> .error_remove_page = generic_error_remove_page,
> + .swap_activate = ext4_iomap_swap_activate,
> };
>
> static const struct address_space_operations ext4_journalled_aops = {
> @@ -3636,6 +3644,7 @@ static const struct address_space_operations ext4_journalled_aops = {
> .direct_IO = noop_direct_IO,
> .is_partially_uptodate = block_is_partially_uptodate,
> .error_remove_page = generic_error_remove_page,
> + .swap_activate = ext4_iomap_swap_activate,
> };
>
> static const struct address_space_operations ext4_da_aops = {
> @@ -3653,6 +3662,7 @@ static const struct address_space_operations ext4_da_aops = {
> .migratepage = buffer_migrate_page,
> .is_partially_uptodate = block_is_partially_uptodate,
> .error_remove_page = generic_error_remove_page,
> + .swap_activate = ext4_iomap_swap_activate,
> };
>
> static const struct address_space_operations ext4_dax_aops = {
> @@ -3661,6 +3671,7 @@ static const struct address_space_operations ext4_dax_aops = {
> .set_page_dirty = noop_set_page_dirty,
> .bmap = ext4_bmap,
> .invalidatepage = noop_invalidatepage,
> + .swap_activate = ext4_iomap_swap_activate,
> };
>
> void ext4_set_aops(struct inode *inode)
> --
> 2.25.1
>
